UNIVERSITY  OF  CALIFORNIA  PUBLICATIONS. 


COLLEGE  OF  AGRICULTURE. 

AGRICULTURAL  EXPERIMENT  STATION. 


RESISTANT  VINES  AND  THEIR  HYBRIDS 


By  E.  H.  TWIGHT. 


BULLETIN  No.  148 

(Berkeley,  October,  1902.) 


SACRAMENTO: 


W.    W.    SHANNON, 


SUPERINTENDENT   STATE    PRINTING. 
1903. 


BENJAMIN  IDE  WHEELER,  Ph.D.,  LL.D.,  President  of  the  University. 

EXPERIMENT  STATION  STAFF. 

E.  W.  HILGARD,  Ph.D.,  LL.D.,  Director  and  Chemist. 

E.  J.  WICKSON,  M.A.,  Horticulturist,  and  Superintendent  of  Central  Station  Grounds. 

W.  A.  SETCHELL,  Ph.D.,  Botanist. 

ELWOOD  MEAD,  M.S.,  C.E.,  Irrigation  Engineer. 

R.  H.  LOUGHRIDGE,  Ph.D.,  Agricultural  Geologist  and  Soil  Physicist.    {Soils  and  Alkali.) 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

M.  E.  JAFFA,  M.S.,  Assistant  Chemist.    (Foods,  Fertilizers.) 

G.  W.  SHAW,  M.A.,  Ph.D...  Assistant  Chemist.    (Soils,  Beet-Sugar.) 

RALPH  E.  SMITH,  B.S.,  Plant  Pathologist. 

GEORGE  E.  COLBY,  M.S.,  Assistant  Chemist.    (Fruits,  Waters,  Insecticides.) 

LEROY  ANDERSON,  M.S.A.,  Animal  Industries,  San  Luis  Obispo. 

A.  R.  WARD,  B.S.A.,  D.V.M.,  Veterinarian,  Bacteriologist. 

E.  H.  TWIGHT,  B.Sc,  Diploma  E.A.M.,  Viticultunst. 

E.  W.  MAJOR,  B.Agr.,  Dairy  Husbandry. 

A.  V.  STUBENRAUCH,  M.S.,  Assistant  Horticulturist  and  Superintendent  of  Substations. 

WARREN  T.  CLARKE,  Assistant  Field  Entomologist. 

H.  M.  HALL,  M.S.,  Assistant  Botanist. 

C.  A.  TRIEBEL,  Ph.G.,  Student  Assistant  in  Agricultural  Laboratory. 

C.  A.  COLMORE,  B.S.,  Clerk  to  the  Director. 


EMIL  KELLNER,  Foreman  of  Central  Station  Grounds. 
JOHN  TUOHY,  Patron, 


>•   Coast  Range  Substation,  Paso  Robles. 


.    Tulare  Substation,  Tulare. 
JULIUS  FORRER,  Foreman, 

R.  C.  RUST,  Patron,  )  

>■   Foothill  Substation,  Jackson. 
JOHN  H.  BARBER,  Foreman,  ) 

S.  D.  MERK,  Patron, 

J.  H.  OOLEY,  Workman  in  charge, 

S.  N.  ANDROUS,  Patron,  )  i  Pomona. 

>•  Southern  California  Substation,   - 
J.  W.  MILLS,  Foreman,      )  (  Ontario. 

V.  C.  RICHARDS,  Patron,         ) 

Y  Forestry  Station,  Chico. 
T.  L.  BOHLENDER,  m  charge,  ) 

ROY  JONES.  Patron,      ) 

V  Forestry  Station,  Santa  Monica. 
WM.  SHUTT,  Foreman,  ) 


The  Station  publications  (Reports  and  Bulletins)  will  be  sent  to  any 
citizen  of  the  State  on  application,  so  long  as  available. 


RESISTANT  VINES  AND  THEIR  HYBRIDS. 


GENERALITIES  REGARDING  RESISTANT  VINES. 
(Abstract  from  Bulletin  No.  131,  by  F.  T.  Bioletti.) 

The  most  satisfactory  method  of  combating  phylloxera  is  the  use  of 
resistant  vines,  because  it  is  applicable  to  all  conditions  and  is  the  most 
economical  in  the  end.  A  resistant  vine  is  one  which  is  capable  of  keep- 
ing alive  and  growing  even  when  phylloxera  are  living  upon  its  roots. 
Its  resistance  depends  on  two  facts:  first,  that  the  insects  do  not  increase 
so  rapidly  on  its  roots;  and  second,  that  the  swellings  of  diseased  tissue 
caused  by  the  punctures  of  the  insects  do  not  extend  deeper  than  the 
bark  of  the  rootlets  and  are  sloughed  off  every  year,  leaving  the  roots 
as  healthy  as  before.  The  wild  vines  of  the  Mississippi  States  have 
evolved  in  company  with  the  phylloxera,  and  it  is  naturally  among 
these  that  we  find  the  most  resistant  forms.  No  vine  is  thoroughly 
resistant  in  the  sense  that  phylloxera  will  not  attack  it  at  all;  but  on 
the  most  resistant  the  damage  is  so  slight  as  to  be  imperceptible.  The 
European  vine  ( Vitis  vinifera,  L.)  is  the  most  susceptible  of  all,  and  all 
the  grapes  cultivated  in  California,  with  a  few  unimportant  exceptions, 
belong  to  this  species.  Between  these  two  extremes  we  find  all  degrees 
of  resistance,  which  is  expressed  by  a  series  of  numbers  ranging  from  20, 
indicating  the  highest  possible  resistance,  to  0,  indicating  the  utmost 
susceptibility.  The  following  table  shows  the  resistance  (according  to 
Viala  and  Ravaz  and  other  authorities)  of  some  of  the  best  known 
species  and  varieties: 

Comparative  Resistance  to  Phylloxera. 

Species  (  Wild  Vines).  Cultivated  Varieties  and  Hybrids. 

Vitis  rotundifolia 19  Gloire  de  Montpellier  (Riparia).  18 

Vitis  vulpina  (Riparia) 18  Riparia  X  Rupestris  3309 18 

Vitis  rupestris 18  Rupestris  Martin _ 18 

Vitis  Berlandieri 17  Rupestris  St.  George 16 

Vitis  aestivalis  .._ 16  Riparia  X  Solonis  1616 16 

Vitis  labrusca 5  Solonis _ 14 

Vitis  Californica 4  Lenoir ..  12 

Vitis  vinifera 0  Isabella 5 

The  degree  of  resistance  necessary  for  the  production  of  good  crops 
varies  with  the  character  of  the  soil.  The  resistance  expressed  by  the 
numbers  16  to  20  is  sufficient  for  all  soils.  A  resistance  of  14  or  15  is 
sufficient  in  sandy  and  moist,  rich  soils,  where  the  vine  can  readily 
replace  the  rootlets  as  fast  as  they  are  destroyed.  Fairly  successful 
vineyards  have  been   established   exceptionally  with  vines    having  a 


4  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

resistance  of  less  than  14,  but  as  the  vines  become  old  the  lack  of 
resistance  is  generally  shown  by  a  weakening  of  the  vine  and  a  falling 
off  of  the  crop.  Many  vineyards  in  the  south  of  France  grafted  on 
Lenoir  which  formerly  bore  well,  have  now  to  be  doctored  with  injec- 
tions of  bisulfid.  For  this  reason  it  is  advisable  to  reject  all  vines 
with  a  resistance  of  13  or  under,  especially  as  vines  with  greater 
resistance  can  now  be  obtained  for  practically  all  conditions. 

Resistant  vines  are  of  two  kinds:  (a)  those  which  are  grown  for  the 
grapes  they  produce,  and  (b)  those  which  are  useful  only  as  stocks  on 
which  to  graft  the  non-resistant  varieties.  The  former  are  called 
"  direct  producers"  the  latter,  "  resistant  stocks" 

(a)  Direct  Producers. — When  the  phylloxera  commenced  to  destroy 
the  vineyards  of  Europe,  the  natural  attempt  was  made  to  replace  them 
with  the  varieties  of  vines  which  had  proved  successful  in  the  United 
States,  where  the  insect  was  endemic.  These  varieties,  however,  all 
proved  unsatisfactory.  Some,  like  the  Concord  and  the  Catawba,  were 
insufficiently  resistant,  and  although  they  could  be  grown  where  the 
severe  cold  of  winter  impeded  the  prolificness  of  the  phylloxera,  they 
quickly  succumbed  in  the  milder  grape-growing  sections  of  Europe.* 
Most  of  them  were  poor  bearers  compared  with  the  prolific  European 
vines,  and  finally  the  character  of  their  fruit  differed  so  widely  from 
what  Europeans  were  accustomed  to  that  there  was  little  sale  for  the 
fruit,  and  the  wine  could  compete  with  only  the  very  poorest  quality  of 
Vinifera  wines,  and  brought  a  very  inferior  price.  A  few  of  the  varieties 
introduced  during  that  first  period  are  still  grown  to  a  limited  extent  in 
France,  chiefly  the  Othello  and  the  Lenoir.  They  are  being  gradually 
abandoned,  however,  as  their  crops  are  unsatisfactory,  and  in  many 
localities  can  be  maintained  only  by  the  aid  of  injections  of  bisulfid. 
For  some  years  the  search  for  a  suitable  direct  producer  was  almost 
abandoned  by  practical  men,  the  use  of  resistant  stocks  having  been  so 
fully  successful.  Lately,  however,  renewed  efforts  have  been  made  and 
several  new  direct  producers  are  being  advocated  and  planted  to  some 
extent.  The  merit  of  these  new  varieties,  however,  is  chiefly  their 
resistance  to  Peronospora  and  Black  Rot.  Phylloxera-resistance  is  con- 
sidered of  much  less  importance  by  their  most  ardent  advocates,  and 
indeed  the  advice  is  given  to  graft  some  of  the  best  of  these  direct  pro- 
ducers upon  phylloxera-resistant  stock.  The  main  importance  of  these 
facts  to  California  grape-growers  is  that  they  hold  out  hopes  of  perma- 
nent prosperity  for  the  wine-making  industry  here,  where,  owing  to  the 
dryness  of  the  climate,  there  is  no  likelihood  of  trouble  from  these 
serious  fungous  diseases  of  the  grape,  which  threaten  to  make  the  grow- 
ing of  Vinifera  varieties  impossible  in  many  parts  of  Europe. 

*In  California,  these  and  other  Labrusca  varieties  and  hybrids  resist  very  little  longer 
than  Vinifera  vines. 


RESISTANT    VINES.  O 

(b)  Resistant  Stocks. — Though  high  resistance  to  phylloxera  is  essential 
in  a  grafting  stock,  there  are  other  characteristics  equally  necessary. 
The  Rotundifolia  (Scuppernong),  which  has  the  highest  resistance  of  any 
vine,  is  useless  as  a  stock  on  account  of  the  impossibility  of  grafting  it  with 
any  Vinifera  variety.  This  is  due  to  a  lack  of  affinity,  which  means  a 
lack  of  similarity  in  structure  and  composition  between  the  tissues  of  the 
stock  and  those  of  the  scion.  This  lack,  in  extreme  cases,  results  in  an 
imperfect  and  temporary  union,  but  when  not  excessive,  only  in  a  slight 
decrease  of  vigor.  The  affinity  is  not  perfect  between  Vinifera  varieties 
and  any  resistant  stock,  but  in  the  case  of  Riparia  and  Rupestris  is 
generally  sufficient  to  insure  permanence  to  the  union,  and  the  slight 
decrease  of  vigor  consequent  often  results  in  an  increase  of  fruitfulness. 
It  is  for  this  reason  that  certain  varieties  when  grafted  on  resistant  stocks, 
especially  on  Riparia,  often  bear  larger  crops  than  when  grown  on  their 
own  roots.  Not  all  varieties  of  Vinifera  have  the  same  affinity  for  the 
same  stock.  For  this  reason  it  is  desirable  to  be  cautious  about  making 
new  or  untried  grafting  combinations  on  a  large  scale.  Some  varieties, 
such  as  Carignan,  Petite  Sirah,  Clairette,  and  Cabernet  Sauvignon,  do 
excellently  on  all  stocks;  while  others,  such  as  Mondeuse  and  Gamay, 
do  not  make  a  very  good  union  with  any  of  the  thoroughly  resistant 
stocks.  The  Petit  Bouschet  and  Cinsaut  make  very  poor  unions  with 
any  variety  of  Riparia,  but  do  fairly  well  on  Rupestris  St.  George.  The 
Pinot  Noir  makes  a  vigorous  growth  upon  Rupestris  St.  George,  but 
bears  much  more  proliflcally  upon  Riparia  Gloire. 

Selection. — A  very  serious  defect  of  many  resistant  stocks  is  a  slender 
habit  of  growth.  This  is  true  of  most  of  the  vines  found  growing  wild, 
and  cuttings  from  such  vines  make  poor  grafting  stock  for  the  stout 
Vinifera  varieties,  which  will  produce  a  trunk  four  inches  in  diameter 
while  the  stock  is  growing  only  two  inches.  This  is  particularly  true 
of  the  wild  Riparias.  For  this  reason  great  care  has  been  exercised  in 
selecting  the  stronger-growing  forms,  and  at  present  we  have  selected 
Riparia  varieties  which  almost  equal  Vinifera  in  the  stoutness  of  their 
trunks.  The  best  of  these  are  the  Riparia  Gloire  de  Montpellier  and 
the  Riparia  Grande  Glabre,  the  first  of  which  has  given  the  best  results 
in  California. 

RESISTANT  VINES  AND  THEIR  HYBRIDS. 
By  E.  H.  TWIGHT. 

If  we  study  the  conditions  affecting  the  adaptation  of  resistant  vines, 
we  see  that  the  amount  of  lime  contained  in  the  soil,  the  degree  of  com- 
pactness, the  moisture,  and  the  fertility  of  the  land  are  the  most 
important  factors.  The  proportion  of  lime  in  the  soil  has  been,  in 
many  countries  and  particularly  in  France,  the  greatest  drawback  in 


6  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT   STATION. 

re-establishing  vineyards  on  resistant  stock.  Happily,  in  California  we 
do  not  have  to  contend  with  that  part  of  the  problem,  as  few  soils  con- 
tain enough  lime  to  affect  even  the  Riparias  and  Rupestris,  that  are 
among  the  first  to  suffer  from  excess  of  carbonate  of  lime. 

The  compactness  of  the  soil,  generally  due  to  the  large  proportion  of 
clay  it  contains,  is  an  obstacle  to  the  good  growth  of  many  varieties  of 
resistant  stock;  the  roots  do  not  penetrate  easily,  the  ground  is  cold 
and  often  wet,  and  under  such  conditions  the  Rupestris  and  Riparia, 
for  instance,  do  poorly.  On  the  contrary,  the  Lenoir,  Champini, 
Riparia  X  Rupestris  No.  3306  and  101u  will  do  well  in  such  locations, 
and  the  hybrids  of  Solonis  X  Cordifolia  X  Rupestris  will  do  still  better. 
The  last-mentioned  have  a  higher  resistance  to  phylloxera  than  Lenoir 
and  Champini.  If  we  examine  the  probable  cause  for  the  special 
adaptation  to  heavy  soils,  we  see  that  whereas  the  Riparia  and  Rupes- 
tris have  light,  thin,  hard  roots  very  much  ramified:  on  the  contrary 
the  varieties  adapted  to  such  soils  have  strong,  fleshy  roots,  less 
ramified,  with  a  heavier  hair  system  on  the  rootlets. 

When  in  excess,  the  moisture  in  the  soil  affects  the  vine  by  checking 
the  growth  of  the  root  system.  Plants  growing  in  a  very  moist  place 
may  have  a  vigorous  aerial  growth,  but  the  root  system  is  generally 
weak;  such  a  plant  will  suffer  greatly  if  for  some  reason  the  supply  of 
moisture  should  fall  below  the  average.  The  root  system  in  a  dry 
exposure  will  always  be  much  more  vigorous,  as  the  plant  has  to  send 
its  roots  lower  down  to  find  the  water  it  needs.  On  the  other  hand,  a 
moist  soil  will  help  a  vine  in  its  fight  against  phylloxera,  and  under 
such  conditions  some  stocks,  though  inferior  in  absolute  resistance,  may 
do  fairly  well.  As  a  general  rule,  the  Solonis  and  its  hybrids  are  very 
good  in  wet  soils. 

The  fertility  of  the  soil  is  a  condition  of  adaptation  that  we  must  not 
overlook:  A  Riparia  or  a  Solonis  will  turn  yellow  and  look  sick  in  a  soil 
where  a  Rupestris  would  do  fairly  well.  This  does  not  mean  that  a 
Rupestris  will  not  do  better  in  a  good  soil  than  in  a  poor  one,  but  simply 
that  it  is  more  rustic  in  its  adaptation. 

VARIETIES    OF    RESISTANT    STOCK. 

We  give  below  the  adaptation  of  the  principal  varieties  of  resistant 
vines  used  as  grafting  stock  or  as  parents  in  the  making  of  hybrids. 
(Riparia,  Rupestris,  Candicans,  Cordifolia,  Monticola,  Arizonica,  Cali- 
fornica,  Berlandieri.) 

Vitis  riparia. — The  V.  riparia  (see  title-page)  is  very  resistant  to 
phylloxera  (18).*  The  grafts  made  on  this  stock  are  fructiferous, 
vigorous,  and  advanced  in  maturity.     All  varieties  root  readily  from 

♦Resistance  to  the  phylloxera  is  indicated  by  figures  on  the  scale  of  20  points. 


RESISTANT    VINES.  / 

cuttings  and  from  grafted  cuttings;  they  also  take  easily  from  field 
grafts.  This  stock  has  often  been  over-boomed,  and  planted  in  many 
localities  where  it  could  never  grow;  and  from  these  failures  some  people 
have  jumped  to  the  conclusion  that  the  stock  is  of  no  value.  But  when 
we  consider  that  in  France  alone,  seventy-two  per  cent  of  the  vineyards 
that  have  been  replanted  are  on  Riparia  roots,  we  readily  see  that  the 
failures  must  be  due  to  the  ignorance  of  the  conditions  of  adaptation. 
Riparias  do  not  grow  well  in  dry  locations;  they  must  have  a  good 
loamy  soil,  the  best  being  clayey-siliceous  alluvions;  a  deep,  cool,  fertile 


PLATE  1.    Vitis  Rupestius  St.  George. 

Showing  on  the  right  the  natural  fold  of  the  leaves  along  the  mid  rib,  and  on  the 

left  the  bracket-shaped  petiolar  sinus. 

soil,  not  too  wet.     The  two  varieties  mostly  used  are  the  Riparia  Gloire 
de  Montpellier  and  the  Riparia  Grande  Glabre. 

Vitis  rupestris. — This  vine,  shown  in  Plate  1,  is  found  in  its  wild  state 
in  open  places  along  hillsides  and  ravines  in  the  arid  eastern  part  of  the 
region,  growing  in  gravels  and  in  decomposed  rocks.     From  this  natural 


8 


UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 


habitat  we  may  see  that  it  will  be  well  adapted  to  light  gravelly  soils, 
hillsides,  and  sandy  soils.  It  is  very  resistant  to  phylloxera  (16-18). 
The  Rupestris  vines  have  a  larger  trunk  than  the  Riparias  and  show, 
after  grafting,  less  difference  between  the  scion  and  stock.  The  cuttings 
root  easily,  but  not  quite  as  well  as  those  of  Riparias;  the  rooting  can 
be  aided  by  scratching  the  bark  of  the  lower  part  of  the  cutting  on  a 
short-tooth  iron  comb.  The  returns  in  bench-grafting  are  about  the 
same  as  those  obtained  with  Riparia.  As  the  Rupestris  cuttings  sucker 
very  much,  it  is  of  great  importance  to  suppress  carefully  the  eyes  on 


PLATE  2.    Vitis  Candicans.    Mustang  Gkape. 
Showing  the  entire  orlobed  leaves  with  the  limb  convex  on  the  upper  face. 
Three  of  the  leaves  are  turned  over,  showing  the  very  thick,  white  felt 
on  the  under  face  of  the  leaves. 

the  stock  when  bench-grafting.  Of  the  two  varieties  that  are  mostly 
used,  the  Rupestris  Martin  is  possibly  a  little  better  adapted  to  dry 
locations.  The  Rupestris  St.  George,  though  well  adapted  to  gravelly 
hillsides  and  light  soils,  has  proved  also,  in  the  last  few  years,  to  be  a 
vigorous  grower,  even  in  lands  where  the  water-table  is  close  to  the 
surface  several  months  in  the  year.     (Letter  from  Prof.  L.  Ravaz.) 

Vitis  candicans. — The  V.  candicans,  or  Mustang  grape  (Plate  2),  found 
in  its  wild  state  in  Texas  and  Arkansas,  grows  generally  on  bottom 


RESISTANT    VINES. 


9 


lands  and  along  rivers,  but  it  is  also  found  in  very  dry  locations;  in 
these,  however,  its  growth  is  not  as  vigorous.  It  does  best  in  alluvial 
soils,  but  its  large  roots  enable  it  to  grow  well  in  heavy  clays.  This 
variety  is  hard  to  grow  from  cuttings,  but  is  very  valuable  in 
hybridization. 

Vitis  cordifolia. — This  vine  is  adapted  to  the  same  class  of  soils  as 
the  V.  riparia;  it  is  very  highly  resistant  to  phylloxera,  and  does  fairly 
well  in  heavy  soils;  it  has  been  also  used  to  great  advantage  in  creating 
hybrids. 


PLATE  3.    V.  Arizonica. 

Vitis  arizonica. — This  vine  (Plate  3)  is  found  mostly  in  Arizona  and 
New  Mexico,  while  numerous  hybrids  of  Arizonica  X  Californica  exist 
in  the  region  where  both  varieties  grow  wild.  It  grows  well  from 
cuttings,  is  nearly  as  resistant  as  Rupestris,  and  ought  to  be  studied 
carefully.  In  adaptation  it  would  hold  a  place  between  the  Riparia 
and  the  Rupestris. 


10  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT   STATION. 

Vitis  monticola. — This  vine  has  only  a  limited  range -of  distribution 
in  Texas,  where  it  is  found  on  lands  similar  to  those  where  the  Rupes- 
tris  grows,  but  containing  generally  a  high  percentage  of  lime.  It  comes 
next  to  the  Berlandieri  as  a  resistant  to  chlorose,  which  is  caused  by 
excess  of  lime  in  the  soil.  This  stock  is  a  very  good  element  in  hybrid- 
izing, and  may  turn  out  to  be  very  valuable  as  a  direct  grafting  stock. 

Vitis  calif ornica. — The  wild  native  vine  of  California;  it  has  a  resistance 
to  phylloxera  too  low  to  be  of  much  use. 

Vitis  Berlandieri. — This  vine  is  found  in  Texas,  New  Mexico,  and 
Mexico,  growing  on  limestone  ridges,  where  it  resists  excessive  drought 
and  heat.  The  quality  of  resistance  to  lime  would  not  be  of  much  interest 
in  California,  but  it  may  prove  to  be  a  very  valuable  stock  in  heavy, 
dry  soils,  as  probably  its  large  fleshy  roots  will  allow  it  to  penetrate 
readily.  Though  the  Berlandieri  does  not  grow  well  from  cuttings,  its 
hybrids  have  not  that  drawback. 

From  these  few  remarks  on  the  principal  resistant  stocks  we  may  see 
that  the  range  of  adaptation  of  each  variety  is  rather  narrow.  This 
observation  led  the  nurserymen  and  the  experiment  stations  in  the 
countries  mostly  interested,  to  try  to  obtain,  by  hybridizing,  new 
varieties  having  a  wider  range  of  adaptation.  This  has  been  done  with 
two  different  objects  in  view.  Some  simply  crossed  the  American 
resistant  varieties  to  obtain  new  grafting  stocks  having  a  larger  range 
of  adaptation;  we  will  call  these  Americo  X  American  hybrids.  Others 
tried  to  cross  the  American  resistant  stocks  with  the  Vinifera-producing 
varieties,  to  obtain  a  resistant  direct  producer;  we  will  call  these 
Vinifera  X  Americans.  So  far  the  latter  have  only  succeeded  in  making 
some  good  grafting  stocks,  the  bearing  qualities  of  the  Vinifera  not 
being  transmitted. 

AMERICO  X  AMERICAN  HYBRIDS. 

Mr.  Munson,  in  the  United  States,  and  a  great  number  of  scientists  in 
Europe  (Couderc,  Millardet,  Grasset,  Foex,  Ravaz)  have  created  a 
large  number  of  new  hybrids,  some  of  the  most  promising  of  which  we 
will  review. 

Riparia  X  Rupestris. — This  group  is  probably  one  of  the  most  inter- 
esting. Among  the  varieties  selected  as  the  best  at  present  we  find 
Nos.  3306  and  3309  of  Couderc  and  No.  101u  of  Millardet.  They  are 
very  resistant  to  phylloxera,  root  easily  from  cuttings,  and  give  a  high 
percentage  of  good  grafts.  The  trunk  increases  rapidly  in  size,  so  that 
there  is  little  difference  between  stock  and  scion;  the  fructification  after 
grafting  is  good  and  regular.     The  range  of  adaptation  is  a  combination 


RESISTANT   VINES   AND    HYDRIDS.  11 

of  that  of  Riparia  and  of  Rupestris;  Nos.  3306  and  101u  being  also 
able  to  do  well  in  soils  a  good  deal  more  compact  in  nature  than  those 
suitable  for  either  of  the  parents;  No.  3309  stands  drought  well. 

Solonis  X  Riparia. — These  hybrids  are  well  known  for  the  heavy- 
bearing  character  they  communicate  to  their  grafts.  The  affinity  is 
very  good  and  they  are  particularly  well  adapted  to  wet  lands.  While 
adapted  to  the  same  soil-conditions  mentioned  above  for  the  Solonis, 
they  have  a  much  higher  resistance  to  phylloxera  than  the  latter. 
The  best  known  are  Nos.  1615  and  1616  (Couderc). 

Solonis  X  Cordifolia  X  Rupestris. — These  have  great  vigor,  which  they 
hold  from  the  Cordifolia  X  Rupestris,  while  they  take  some  of  the 
characters  of  the  Solonis  in  moist  locations.  They  have  proved  very 
valuable  in  heavy  moist  clays.  No.  202*  of  Millardet  and  Grasset  is 
among  the  best. 

Riparia  X  Cordifolia  X  Rupestris  (No.  1068). — Is  very  similar  to  the 
last  group  regarding  its  vigor,  but  is  adapted  more  particularly  to  very 
arid  locations,  where  it  has  proved  superior  even  to  the  Rupestris 
Martin.     It  will  probably  be  of  great  value  in  some  of  our  adobe  lands. 

Berlandieri  X  Riparias. — These  hybrids  have  been  studied  in  France, 
mainly  to  create  a  stock  having  the  resistance  of  the  Berlandieri  to 
chlorose,  and  the  easy  rooting  of  the  Riparias.  Some  of  the  selections 
have  given  very  satisfactory  results  (157,  420,  34E).  The  Berlandieri 
hybrids  are  very  productive  after  they  have  been  grafted.  The  roots 
are  very  strong  and  both  surface  and  deep  roots  are  abundant;  as  we 
said  before,  this  hybrid  may  prove  to  be  very  valuable  in  stiff,  dry  soils. 

VINIFERA  X  AMERICAN  HYBRIDS. 

Lenoir. — Though  the  question  of  the  origin  of  the  Lenoir  is  not  very 
well  settled,  it  probably  comes  in  this  group  of  Vinifera  X  American. 
The  Lenoir  has  a  great  affinity  for  the  Viniferas,  so  that  when  grafted 
in  the  field  it  gives  very  good  results.  It  does  not  root  as  well  from 
cuttings  and  does  not  bench-graft  as  well  as  the  Riparias  and  Rupestris, 
but  still  gives  satisfactory  results.  The  resistance  to  phylloxera  is  not 
high  (12-13),  which  is  too  low  unless  it  is  planted  in  a  soil  perfectly 
adapted  to  its  growth.  In  rich  soils,  fertile,  and  with  plenty  of  moisture, 
it  does  very  well,  but  these  are  also  good  Riparia  soils.  When  the  soil 
becomes  compact,  then  the  Lenoir  would  do  better  than  the  Riparia. 
But  for  these  heavy  lands  we  have  to-day  such  varieties  as  the  Solonis  X 
Cordifolia  X  Rupestris,  the  Riparia  X  Cordifolia  X  Rupestris,  the 
Riparia  X  Rupestris  101 u,  which  are  far  superior  to  the  Lenoir  in 
resistance,  and  ought  therefore  to  receive  the  preference. 


12  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION. 

Mourvedre  X  Rupestris  or  Mataro  X  Rupestris  is  a  very  fine  selection 
of  Vinifera  X  American;  the  1202  grows  well  in  all  soils  from  a  chalky 
land  to  a  deep  alluvial  one.  It  has  been  found  quite  resistant  to 
phylloxera,  and  particularly  well  adapted  to  heavy  clay  soils. 

Bourrisquou  X  Rupestris  and  Carignane  X  Rupestris  have  also  a  large 
range  of  adaptation,  but  are  specially  adapted  to  dry  locations. 

Aramon  X  Rupestris  (1  and  2)  are  found  to  do  splendidly  in  clay 
soils  of  medium  fertility  and  in  soils  underlaid  with  clay.  We  have  a 
great  many  of  these  soils  in  California,  and  this  stock  may  prove  to  be 
of  great  value.  The  roots  are  superficial,  like  those  of  the  Riparias, 
but  they  are  large  and  fleshy. 

MUNSON  HYBRIDS. 

Mr.  Munson  has  created,  in  recent  years,  a  great  many  hybrids  of 
Americo  X  Americans  and  of  Vinifera  X  Americans;  some  of  these  are 
quite  promising,  but  the  local  results  that  have  been  published  at 
different  times  can  not  be  taken  as  final  proof  of  their  value.  We  have 
not  yet  sufficient  data  to  give  personal  observations  on  these,  but  will 
give  the  opinion  of  Professors  Viala  and  Ravaz,  the  French  viticultural 
authorities,  on  some  of  the  Munson  resistant  stocks. 

Vitis  champini  (Candicans  X  Rupestris). — Can  be  divided  in  two 
groups:  the  glabrous  and  the  tomentose.  The  glabrous  group  has  a 
resistance  of  14,  the  tomentose  of  12.  They  are  harder  to  grow  from 
cuttings  than  the  Rupestris,  but  have  the  advantage  of  being  good 
growers  in  heavy  clays  and  of  having  large  wood.  Their  low  resistance 
is,  however,  a  grave  objection,  especially  when  we  have  some  varieties 
that  do  just  as  well  in  the  same  locations  and  which  are  much  more 
resistant. 

Candicans  X  Monticola  (Gwyn,  Sanford,  Belton).— The  latter  is  prob- 
ably the  best;  it  has  a  resistance  of  16,  is  very  vigorous,  has  a  large 
trunk,  does  well  in  compact  soils,  and  has  large  wood,  but  does  not 
grow  well  from  cuttings. 

Novo-Mexicana. — This  is  probably  a  Candicans  X  Riparia  X  Rupes- 
tris. The  Solonis,  Moobetie,  Hutchison,  and  Doaniana  are  some  of  the 
varieties  of  this  group.  They  are  adapted  to  Solonis  soils;  that  is,  rich, 
with  plenty  of  moisture.  They  do  well  in  lands  that  are  rather  wet 
and  salty  (alkali).  They  grow  well  from  cuttings  and  have  good-sized 
wood.  The  resistance  to  phylloxera  is  not  first  class,  but  is  sufficient 
in  soils  well  adapted  to  them.  In  lands  not  well  adapted,  they  suc- 
cumb rapidly  to  the  attacks  of  the  insect.  The  Hutchison  is  more 
vigorous  and  resistant;  the  Solonis  and  Doaniana  less  so. 


RESISTANT    VINES   AND    HYBRIDS.  13 

RESPECTIVE  VALUE  OF  AMERICO  x  AMERICANS  AND  VINIFERA  x  AMERICANS. 

We  have  seen  that  in  both  of  these  groups  of  hybrids  we  may  find 
some  varieties  that  are  well  adapted  to  our  special  conditions;  in  both, 
we  find  a  good  resistance  to  phylloxera  in  the  selected  stock.  Which  of 
these  should  we  plant  in  our  vineyards? 

It  may  be  said  in  a  general  way  that  the  Americo  X  American 
hybrids,  as  well  as  the  ordinary  American  grafting  stocks,  make  the 
Vinifera  scions  that  are  grafted  on  them  bear  more  heavily  than  they 
would  if  they  were  on  their  own  roots.  They  come  into  full  bearing 
earlier,  and  generally  the  fruit  will  ripen  a  few  days  earlier.  But  the 
variety  of  Vinifera  grafted  on  these  roots  does  not  reproduce  exactly 
the  type  it  represents  when  on  its  own  roots:  the  grapes  may  be  larger, 
but  there  is  a  slight  difference  in  the  flavor  and  the  per  cent  of  sugar. 
The  Vinifera  vines  grafted  on  Vinifera  X  American  hybrids  retain  better 
their  original  qualities  and  have  a  better  affinity  between  stock  and 
scion. 

The  heavy  bearing  of  the  vines  grafted  on  Americans  or  on  Americo  X 
American  will  exhaust  the  land  sooner;  so  that  fertilizing  will  have  to 
be  resorted  to  earlier,  and  it  is  a  known  fact  that  heavy  fertilization 
affects  the  quality  of  the  grapes. 

From  these  remarks  we  may  conclude  that  the  American  resistant 
stock  and  their  hybrids  will  probably  be  favored  by  those  who  look  to 
quantity  more  than  to  quality;  while  for  the  fancy  wine  grapes  and  the 
better  grades  of  table  and  raisin  grapes  the  Vinifera  X  American 
resistant  stock  will  be  chosen.  The  choice  between  the  two  groups  is 
mainly  an  economic  question. 

A  warning  must  be  given  regarding  the  selection  of  the  stock.  We 
find  hundreds  of  thousands  of  hybrids  of  each  kind,  but  only  very  few 
have  been  carefully  selected.  Because  the  Riparia  X  Rupestris  3306  or 
3309  are  good,  it  is  by  no  means  a  reason  for  any  " Riparia  X  Rupestris" 
to  be  equally  good.  The  number  of  the  selection  is  as  important,  and  in 
fact  more  important,  than  the  name  of  the  stock. 


